For some time, as set forth in Patent Document 1 (EP 2568089 A1), it is known that the flush water tank apparatuses is disposed so as to be concealed within the area in the reverse side of a wall surface as a flush water tank apparatus for supplying flush water to a flush toilet. Flush water is supplied from a concealed flush water tank apparatus concealed in the reverse side of a wall, to a flush toilet attached to the front surface of a wall.
Further, as set forth in Patent Document 2 (JP 2015-196949 A), it is known that a flush water tank apparatus comprises a handle attached to the outside of a reservoir tank, a shaft member extending so as to penetrate the side surface of the reservoir tank from this handle, a manual operation unit communicating with the shaft member inside the reservoir tank, and a power drive unit provided inside the reservoir tank, driven by a motor. In such a flush water tank apparatus, a wire is raised by the manual operation unit and the power drive unit, whereby a valve body in the discharge valve apparatus is raised, thereby flush water in the reservoir tank is discharged and the toilet is flushed.